This proposal aims to develop a nanoscale electrochemical sensor that will be used to determine the role gliotransmitters play as intercellular signaling molecules in the central nervous system. The sensing platform will combine the chemical specificity afforded by electrochemical, aptamer-based sensors with the exquisite spatiotemporal resolution afforded by nanoscale electrodes and will be amenable to use with patch clamp instrumentation. The aims of the proposal are two-fold. First, the fabrication, characterization and optimization of nanoscale, electrochemical aptamer-based sensors will lead to high-performance sensors capable of specifically monitoring adenosine triphosphate (ATP) release from astrocytes. Second, sensors will be used to determine the dominant mechanism(s) of ATP release and whether ATP release and mechanisms are localized to specific regions of the astrocyte. The initial focus in this proposal will be the development of in vitro measurements with the nanosensors on cultured astrocytes. However, because the sensors developed function in complex biological media, they will, in the longer term, be applied to more physiological models (brain slices) and ultimately optimized for use in vivo to elucidate the role of ATP as a signaling molecule. The long-term goal of the research is to understand the molecular basis of glial cell communication in order to accelerate discoveries and reduce the burden of nervous system disorders. The proposed studies will yield a cutting edge tool that that is capable of transforming glial cell research by providing methodology to understand function in the central nervous system.